A square loop of side 10cm and resistance 0.5$\mathrm{\Omega }$ is placed vertically in east-west plane. A uniform magnetic field of 0.1 tesla is setup across the plane along northeast direction. The magnetic field is decreased to zero in 0.7 seconds. The induced current is 
 

Given data: $\text{ loop of side }10 \mathrm{cm}$, resistance $0.5\Omega$, $\text{ magnetic field of }0.10 \mathrm{T}$, decreasing magnetic field to zero in $0.7 \mathrm{s}$

Concept used: electromagnetic induction.

Detailed solution:

A current is created by voltage production as a result of shifting magnetic field.

$$\begin{gathered} \varphi =\text{BA}\cos \theta \\ {\varphi }_{\min }=0 \\ ϵ=\frac{\text{dϕ}}{\text{t}}=\frac{{10}^{-3}}{\sqrt{2}\times 0.7}=1.0\times {10}^{-3}=1\text{mV} \\ \text{I}=\frac{ϵ}{\text{R}}=\frac{{10}^{-3}}{0.5}=2 \text{mA} \end{gathered}$$.